Difference between Honda t-stats BF25

[walexa]

I have a NOS honda t-stat for the 2003 and older honda BF25, it is stamped with 72C. My BF25 is a 2004, t-stat housings and covers and gaskets are identical, so physically this older t-stat will work..........yet in 2004 they went to a new part number. Does anyone know if it was just a temp change, or higher flow, etc? I would like to use this t-stat in my engine but don't want to do damage.

2003 & older part #: 19300-ZV5-043
2004 & newer part #: 19300-ZW9-003

Waylan

 

[hondon]

Re: Difference between Honda t-stats BF25

That is a temp change to hopefully avoid water intrusion and increase fuel efficientcy.These triples really do'nt like being run cold and make alot of oil when they do.When your oilpan becomes overfilled ,alot of bad things can happen.

 

[walexa]

Re: Difference between Honda t-stats BF25

Hondon,

Thanks for the response. Do you know what the temp is of the t-stat for 2004 and newer? 72C is about 162F.

And if I changed my oil more regularly, would I be ok to run the 72C? Were there any other problems other than dilution of engine oil with gasoline?

Waylan

 

[marquette]

Re: Difference between Honda t-stats BF25

i don't to jump on anybodies thread with this question. i have a 1998 BF30a which as far as i can tell uses the same Tstat part #. i troll a lot and have problems with making oil. can i go to the newer T-stat and solve some of the problem? is going to a higher temp Tstat Honda's solution to the problem?

 

[walexa]

Re: Difference between Honda t-stats BF25

Marquette,

My outboard is actually a 2004 BF30.........but they use the same t-stats for same year models, I just didn't want to complicate by using 2 different models.

Back to your question..........I troll very little, but let it idle for 5-10 minutes at a time between putting out hooks, less than that when running the hooks. The rest of my running is 3/4 to full throttle, and my engine still makes a considerable amount of oil. And mine has the updated t-stat. I run my engine in 50F to 90F fresh water in Louisiana.What I don't understand is why the new t-stat has not superceded the older "cooler" one. That is why I am interested in the temp on the new one. Regardless, the new t-stat is not a magic bullet to prevent "making oil".

Can anyone give me the temp that should be stamped into the new t-stat?

Thanks.

 

[hondon]

Re: Difference between Honda t-stats BF25

You have to be a little carefull here about the info that parts person is using, and how they interpret that info.If they are still clinging to the old parts pages ,those updates will not be there.If they are on I.N. or PARTSMART they will still have to scroll down to the most recent number.Making oil has always been an issue with 4 stroke o.b.s .There are more causes than running too cold.Improper propping or lugging this thing will do it to you,as will substandard fuel,misadjusted valves,poor compression,carbs that are not properly in sync.Essentially,anything that leads to some degree of incomplete combustion.That spent and unused fuel has no where else to go but into the oil pan and SOO,makes oil.These triples do'nt like to be out of that state of tune and do'nt like to run too cold,but love the high end of they,re idle spec.

 

[marquette]

Re: Difference between Honda t-stats BF25

thanks for the info about being in proper tune to prevent (slow down) making oil. i have thought all summer my motor hasn't been running right at wot. i'm about 500-800rpm below where i should be. i never thought that could be contributing to the excess oil the engine was making.